dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 638

• Manufacturer Part Number: dsp56800e
• Description: 16-bit Digital Signal Controller Core
• Manufacturer: Freescale Semiconductor, Inc

TST
Operation:
S – 0
S – 0
Description: Compare the specified source accumulator (S) with zero, and set the condition codes accordingly. No
Example:
Explanation of Example:
Condition Codes Affected:
A-294
Before Execution
A2
8
(no parallel move)
(one parallel move)
result is stored, although the condition codes are updated. The result is not affected by the state of the
saturation bit (SA).
TST
Prior to execution, the 36-bit A accumulator contains the value $8:0203:0000, and the 16-bit SR con-
tains the value $0300. Execution of the TST instruction compares the value in the A register with zero
and updates the CCR accordingly. The contents of the A accumulator are not affected.
SZ — Set according to the standard definition of the SZ bit (parallel move)
L
E
U
N
Z
V
C
LF
15
— Set if data limiting has occurred during parallel move
— Set if the extension portion of accumulator result is in use
— Set according to the standard definition of the U bit
— Set if bit 35 of accumulator result is set
— Set if accumulator result equals zero
— Always cleared
— Always cleared
0203
P4
14
A1
A
13
P3
SR
P2
12
MR
DSP56800E Core Reference Manual
P1
11
X:(R0)+N,B
0000
0300
A0
Test Accumulator
P0
10
I1
9
Assembler Syntax:
TST
TST
I0
8
;set condition codes for the value
;in A, update B and R0
SZ
7
After Execution
6
L
A2
8
5
E
S
S
U
4
CCR
0203
A1
N
3
(no parallel move)
(one parallel move)
SR
2
Z
Freescale Semiconductor
V
1
0000
0338
C
0
A0
TST